Not Applicable
The present invention is directed to in-floor raceway wiring systems, and more particularly to a wire pull grommet for preventing high-speed communications cabling from being bent excessively at the transitions between adjacent raceway components, including at the transition from between an activation box, such as a preset, and the cellular raceway, and at the transition between a cellular raceway and a feeder duct.
Modem office buildings require electric power, communication, and computer data services in various combinations at a large number of locations. Often these needs are addressed by in-floor cellular raceway systems. Cellular raceway systems typically include a cellular metal deck or cellular raceway, which rests directly on the subfloor. The cellular raceway includes a central portion or cell for carrying power cables and a pair of communication/data cells on opposite sides of the power cell. One of the communication cells may carry telephone cable and the other may carry computer, data, or other low potential cables. In addition, the cellular raceway system may include a series of feeder ducts for feeding power and communications cabling from the supply (distribution) closet and to the cellular raceway. The feeder ducts typically run perpendicular to and above the cells of the cellular raceway. Both the cellular raceway and the feeder ducts are covered with concrete for the finished floor. Access to the underfloor service raceways is obtained through activation boxes in the form of presets and aftersets, for example. Presets are activation boxes are mounted on the raceways at desired locations before the concrete floor is poured, whereas aftersets are mounted on the raceway after the floor is poured. The activation box defines a hollow interior compartment interconnected with the interiors of the raceway cells to provide access to the services that are carried in cells. In use, cables are routed from the supply closet, through the feeder duct, into the raceway cells, and in turn into the activation box.
Certification standards, such as Underwriters Laboratories (UL) and the National Electric Code, require the transitions between raceway components, such as the opening between the preset and the cell, be grommeted so as to protect cables from being abraded and damaged as they are pulled through the opening. Similarly, current EIA/TIA standards require that any opening that will be used to pull category 5 type data cable or fiber optic cable must have a feature that will prevent cable from being damaged when pulled around a corner.
Wire abrasion has typically been addressed via a rubber ring, which is press fit around the edge of the opening to protect against abrasion by eliminating sharp metal edges. While these rubber rings are suitable for use with telephone and low-speed communications cables, such as telephone lines, they are not acceptable for use with modem, high-speed data cabling such as fiber optics and category 5 cabling. In particular, excessive bending of high-speed data cable has dramatic, negative effects on the data transmission rates through such cabling. The traditional press-fit grommets discussed above are not satisfactory because they do not provide any means for preventing excessive bending of the cables, but instead merely function to prevent wire abrasion. One potential solution is to design the raceway system to include rounded comers at the junctions of its adjacent components and to include rounded wire pull openings with sufficient bend radiuses. However, this xe2x80x9csolutionxe2x80x9d requires costly retooling and offers no solution for buildings where the cellular raceway systems were installed prior to the implementation of these requirements. Alternatively, some raceway systems rely on the installers to ensure that the cabling is not bent beyond the minimum bend radius. As is readily apparent, this xe2x80x9csolutionxe2x80x9d is ripe with pitfalls. For example, although the cabling may ultimately installed with the correct bend radius, it is possible for the cables to be bent excessively during installation, which can damage the cabling and adversely effect transmission rates through the cabling. Hence, there is a need for a grommet that can be installed in wire pull openings to ensure that high-speed communications cables are not subjected to excessive bending. Moreover, there is a need for a grommet that can be installed into existing raceway systems to bring these applications into compliance with current certification standards. There is also a need for a wire pull grommet that can be installed into an existing raceway installation without disconnecting the cabling.
One object of the present invention is to provide a grommet for mounting in a wire pull opening of a cellular raceway system and which prevents high-speed communications cables from being bent excessively.
Another object of the present invention is to provide a grommet for mounting in a wire pull opening extending between an activation box and a cell of a cellular raceway system and which prevents high-speed communications cables from being bent excessively.
Another object of the present invention is to provide a grommet which can be mounted at the junction of a feeder duct and a raceway cell to provide prevent excessive bending of high-speed communications cables.
Another object of the present invention is to provide a grommet for mounting in a wire pull opening that provides a smooth, radiussed surface for pulling wires.
Still another object of the present invention is to provide a wire pull grommet that has a passage defining a wire pull strain relief.
Yet another object of the present invention is to provide a wire pull grommet that includes a wire storage section for storing excess.
A further another object of the present invention is to provide a wire pull grommet that can be mounted in different sizes of wire pull openings.
Another object of the present invention is to provide a wire pull grommet having a wire storage portion around which excess wiring can be wrapped.
Another object of the present invention is to provide a wire pull grommet that is low cost and economical to manufacture.
Yet another object of the present invention is to provide a wire pull grommet that is durable and easy to install.
Another object of the present invention is to provide a wire pull grommet that can be retrofit into existing cellular raceway systems.
A further object of the present invention is to provide a wire pull grommet that can be retrofitted into existing cellular raceway system without the disconnection of previously installed cabling.
These and other objects and advantages are achieved by a wire protection grommet constructed for installation in a wire pull opening of a cellular raceway. A wire protection grommet is constructed for installation in a wire pull opening in the cell of a cellular raceway. The grommet is sized for insertion through the wire pull opening and defines central passages extending through the opening. The central passage has a radiused portion defining a wire pull strain relief to prevent wires that pass through the grommet from being bent beyond a predetermined bend radius. The grommet is constructed to lockingly engage into the wire pull opening so that it is not displaced during use. The distal end of the grommet may be weighted so that the grommet correctly orients itself in the opening during installation. The grommet may also include a wire storage section around which excess wiring can be wrapped. Hooks may be provided for retaining the excess wire on the wire storage section. The grommet may include an opening or slot which extends to the central passage and which is sized to permit wires to be slid into the passage. The grommet may be configured for installation in a variety of opening sizes and shapes and at the transitions between various components of the raceway system, such as between the raceway cell and an activation box or between the raceway cell and a feeder duct.